Optimizing the boiler start time based on the outside temperatures can help you drive down energy bills


Saving energy and money by optimizing the way in which a central heating system works should be very high on the priority list for all home or business owners, considering the fact that energy prices have started to go up again.

If your current heating is controlled by a time clock, it turns on your boiler so that rooms are warm at a specific time. It does this irrespective of the outside temperature – because it doesn’t know it. A number of traditional BMS systems do this too, while some have something called “adaptive start” which goes someway towards taking into account the outside temperature.

Why is the outside temperature important? Well, in winter, the outside temperature 1st thing in the morning can be -5°C on one day and +12°C the next, so HeatingSave calculates the “heat loss profile” of your specific building using the current outside and inside temperature to work out the absolute latest time to switch on the boiler for the rooms to be warm for when you want them. Equally, HeatingSave switches off the boiler early on warm days at the end of the heating period.

Normal central heating time clocks turn on the central heating the same time every day irrespective of
• the outside weather conditions
• the residual heat within the heating zone or building
• the heat loss profile of the heating zone or building

Within HeatingSave each heating zone is managed independently; a heating zone defined as area within a building, a hot water cylinder(s) or even the whole building itself. The reason why time clocks cannot manage heating to this level is because they are dumb with no intelligence and many BMS systems can’t reach this level of control either.

Heating Save is different. It has a mathematical algorithm (a series of quadratic equations) which have been designed to calculate and “learn” the heat loss profile of any heating zone. So long as the plumbing allows the control of the flow of heat into the zone, HeatingSave can calculate the heat loss profile of the zone. Armed with this information, the HeatingSave controller works out the latest time to switch on the heating for the given conditions, so as to reach the temperature you have set for a given time.

In practice, HeatingSave will start the boiler later on warm days and/or if the zone has a large amount of residual heat, and starts the boiler earlier if the building is cold or its cold outside. The reverse happens at the end of a heating period. Here, heating to a zone is switched off early if the residual heat within the zone can be maintained at the required temperature until the end of the heating period.

As can be seen from the picture top right, the HeatingSave algorithm is learning and refining its decision making process every day it’s in operation, all the time keeping at the right comfort conditions whilst saving the maximum amount of heating fuel.


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